function restore_error_handler() {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // *     example 1: restore_error_handler();
  // *     returns 1: true

  // Fix: Docs suggest can revert to built-in function; where/how is it set? in ini somewhere?

  if (!this.php_js || !this.php_js.previous_error_handler) {
    return true; // function always returns true
  }

  this.php_js.error_handler = this.php_js.previous_error_handler;

  return true;
}
